Apparatus for processing plastic materials

ABSTRACT

An apparatus for extruding, injection molding, blow molding and transfer molding plastic materials comprises a feed screw rotating in a barrel and feeding plastic material over a revolving member surrounded by an increasing and a decreasing housing with a discharge opening at its center. The revolving member has an increasing surface with an axis which has a radial distance to the center line of the increasing housing. The revolving member has a subsequent decreasing surface with that axis which has a radial distance to the middle line of the decreasing housing diametral to the radial distance from the center line of the increasing housing surface to that axis of revolution, so that the forces developed in an area of decreasing surfaces are compensated by forces in a diametral area of increasing surfaces. The increasing surfaces diverge from each other as do the decreasing surfaces. The increasing housing, the decreasing housing and the revolving member are axially movable relatively to each other to vary the spaced relationship between their surfaces. For extrusion, an extrusion barrel is attached to the decreasing housing, and an extrusion screw to the revolving member. For molding operations, an injection screw or an injection piston extends through a bore in the revolving member coaxial with the member&#39;&#39;s axis of revolution.

United States Patent 191 Eckhardt Oct. 15, 1974 [54] APPARATUS FORPROCESSING PLASTIC MATERIALS [76] Inventor: Hans A. Eckhardt, 55 CresentBend,

Allendale, NJ. 07401 22 Filed: Apr. 3, 1972 21 Appl.No.:240,444

Primary ExaminerR. Spencer Annear [5 7] ABSTRACT An apparatus forextruding, injection molding, blow molding and transfer molding plasticmaterials coma a a prises a feed screw rotating in a barrel and feedingplastic material over a revolving member surrounded by an increasing anda decreasing housing with a discharge opening at its center. Therevolving member has an increasing surface with an axis which has aradial distance to the center line of the increasing housing. Therevolving member has a subsequent decreasing surface with that axiswhich has a radial distance to the middle line of the decreasing housingdiametral to the radial distance from the center line of the increasinghousing surface to that axis of revolution, so that the forces developedin an area of decreasing surfaces are compensated by forces in adiametral area of increasing surfaces. The increasing surfaces divergefrom each other as do the decreasing surfaces. The increasing housing,the decreasing housing and the revolving member are axially movablerelatively to each other to vary the spaced relationship between theirsurfaces. For extrusion, an extrusion barrel is attached to thedecreasing housing, and an extrusion screw to the revolving member. Formolding operations, an injection screw or an injection piston extendsthrough a bore in the revolving member coaxial with the members axis ofrevolution.

22 Claims, 8 Drawing Figures 38 so 82 a4 4 Ti l9 39 72 as APPARATUS FORPROCESSING PLASTIC MATERIALS BACKGROUND OF THE INVENTION The presentinvention relates to apparatus for processing plastic materials, and inparticular to apparatus and methods for extruding, injection molding,blow molding, transfer molding, and otherwise transforming plasticmaterials.

To extrude, injection mold, blow mold, and transfer mold plasticmaterial it is necessary to heat, compress, mix, disperse, shear, work,degas and convey the material, and it is combinations of thesetreatments which will be referred to in this specification asprocessing. Plastic materials are defined in this specification asmaterials exhibiting viscous as well as elastic behavior while beingprocessed.

For extruding, injection molding, blow molding, and transfer molding ofplastic materials screw machines have been in use for a long time,primarily consisting of a barrel with a cylindrical bore, a die at oneend, a feed opening at the other end, and one or more screws rotatingtherein with close clearance. In spite of many improvements, for examplein screw design, these conventional screw extruders often perform thetask of processing not efficiently or uniformly, one of the reasonsbeing that screw machines have been acknowledged to be suitable meansfor conveying and compressing, but much less for efficient, measured anduniform heating, mixing, dispersing, shearing and working.

There are other extruders known which employ two parallel plates, one ofthem rotating, wherein the plastic material is worked in the spacebetween the flat opposite faces of these plates, and is dischargedthrough a central orifice in the stationery plate. These extruders makeuse of a natural phenomenon, the normal force effect, which has beendescribed in the scientific literature during the past few decades. Themost widely known illustration of the normal force effect has been givenby K. Weissenberg in Nature, Mar. 1, 1947, Vol. 159, p. 3 l3l l, and adetailed description of applications in Modern Plastics" magazine ofOctober, 1959, page 107, in an article of Bryce Maxwell and Anthony J.Scalora. Machines built along these lines have been called centripetalextruders, or elastic melt extruders.

While centripetal extruders offer several advantages, their practicalapplication has been very limited by a number of drawbacks. One of thedisadvantages is the fact that at the start-up the plastic materialparticles fed in the form of powder, flake, beads or granules falldownward within the air space between the rotating and the stationarysurface to the bottom of the heating chamber where they often caketogether to such an extent that they are not brought back up between ther0- tating and the stationary surface even by auxiliary means, andprevent further uniform feeding. Another drawback is that other plasticmaterial particles reach the center of the two plates without havingundergone suitable conditions of temperature, pressure, and mechanicalworking, and therefore constitute portions of lower temperature andhigher viscosity in the extrudate which thus becomes unusable.Oftentimes the die orifice is getting clogged by such harder and colderparticles.

A further disadvantage is that the plastic material fed in the form ofpowder, flake, beads or granules has, for some time after entering thespace between the rotating and stationary disks, neither a viscous noran elastic behavior, and therefore is more exposed to gravitationalforces letting it fall through to the bottom of the heating chamber, andto centrifugal forces preventing continuous and uniform feeding ofmaterial than to centripetal forces as desired. In addition, with biggermachines having larger plate diameters, even such particles which haveachieved elastic and viscous properties, are travelling at such a largediameter are that the centripetal effect is unable to overcome thecentrifugal forces, thus interrupting the desirable uniform spiral flowtoward the center.

Another known device uses a screw to feed plastic material in the spacebetween the smaller ends of a conical stator and a conical rotor,sometimes equipped with ribs. Such devices have been found to besuitable only for a very small number of plastic materials, for aboutone type out of one hundred, while all the other plastic material typeshave shown excessive decomposition and overheating a short time afterthe start-up, thus rendering the device unusable. Even with one of thefew applicable materials the product emerges from the unobstructedcylindrical space in form of irregularly shaped chunks which require anadditional extruder or injection molding machine for final process ing.If an extruder is attached, the irregularly shaped chunks have to berestructed in their unimpeded exit from the annular space in order toemerge only at a small segment at the top of the annular space fromwhere they drop into the extruder chute; they suffer considerable heatlosses, undesirable oxygen contact due to the difficulties ineffectively enclosing such aggregate equipment for evacuating andpurging, and oftentimes agglomeration of the sticky, tacky chunks in theextruder chute, thus interrupting continuous extrusion.

Another well known device for processing plastic materials is a two rollmill, with plastic material fed to the adjustable nip wherein it isworked quite effectively. However, the two roll mill is not consideredto be a modern continuous processing machine because of the batchoperation, the dependence on human skills, the high pressures developedin the linear nip and the exposure to oxygen.

SUMMARY OF THE PRESENT INVENTION The present invention is directed to anapparatus for processing plastic materials which eliminates thedifficulties heretofore described. The invention provides apparatuswhich pressure feeds the particular material to an adjustable annularspace of increasing circumference having a width varying over thecircumference between a maximum and minimum width, so that a widevariety of plastic materials, including heat sensitive materials, can besheared, worked, mixed and dispersed reliably and effectively.

The apparatus of the invention feeds the sheared and worked plasticmaterial from the entire circumference of the annular space ofincreasing circumference, without restriction to a small segmentthereof, to the entire periphery of an annualr space of decreasingcircumference with a width varying over that circumference diametrallyto that of the increasing circumference, so

that the processing pressures developed compensate each other in axial,radial and diametral directions.

The apparatus of the invention avoids heat losses and agglomeration ofplastic material emerging from the annular space of increasingcircumference and varying width, and provides apparatus for working theplastic material in a subsequent annular space of decreasingcircumference and diametrally varying width. Furthermore the inventionavoids oxygen contact and porosity of the plastic material, and subjectsthe plastic material to vacuum or a protective gas atmosphere byremoving the air through a duct near the transition from the annularspace of increasing varying circumference, to the annular space ofdecreasing varying circumference.

The apparatus of the invention prevents powder, flake, beads or granulesfrom dropping through the air spaces between working surfaces to thebottom of a processing machine during start-up and shut-down periods,and provides processing spaces approaching zero width in a diametrallyvarying operation during such periods, so that the plastic material isworked in nar row, diametrally varying annular spaces. The inventionavoids caking and agglomeration of plastic material particles in spacesoutside the working surfaces of a processing machine, and providesapparatus having annular spaces of diametrally varying widths subjectingthe plastic material to continuous flow in axial, radial and circulardirections, thus eliminating stagnation.

The invention prevents material particles from reaching the dischargeopening of a processing machine and clogging the die orifice withouthaving undergone effective plastification by mechanical working, heatand pressure, and provides apparatus exposing the plastic material tosufficiently high shearing stresses, temperatures and pressures. Theinvention avoids material particles without viscous and elastic behaviorentering the space between surfaces effecting centripetal movements, andprovides apparatussubjecting only plastified material with viscous andelastic characteristics to centripetal processing.

The apparatus of the invention subjects plastic material to twodifferent principles of mechanical working, by shearing, stretching,milling, kneading, mixing, and dispersing the material first in anincreasing conical annular space between an increasing conical revolvingmember surface and an increasing conical housing surface disposedeccentrically to the axis of revolution, and subsequently in adecreasing conical annular space between a decreasing conical revolvingmember surface and a decreasing conical housing surface eccentric to theaxis of revolution, with a circular roll mill treatment over thecircumference of these surfaces taking place in a diametral manner sothat the axial and radial forces compensate each other. The inventioneliminates the aggregation of thrust loads and of radial forces incertain directions and provides apparatus compensating the rearwardthrust by a forward thrust, and compensating radial forces in onedirection by radial forces in the diametral direction.

The invention shortens the length of a processing machine and providesapparatus for working plastic material first in an annular conical spaceincreasing in axial direction and subsequently in a conical annularspace decreasing in reverse axial direction, with the widths of the twospaces varying diametrally with each other. The invention preventsplastified hot material from remaining in an irregular shape for anyperiod of time and provides apparatus for uninterruptedly working theplastic material. Furthermore the invention eliminates the use of screwsas main tools for shearing, kneading, mixing and dispersing plasticmaterial, and provides apparatus for shearing, kneading, mixing anddispersing plastic material in annular conical spaces of increasing andsubsequently decreasing circumferences, having radial widths varyingdiametrally over the circumferences, with a circumferential roll millaction taking place in these spaces, so that the minimum radial width ofthe increasing space is diametrally positioned to the minimum radialwidth of the decreasing space.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be moreparticularly described in reference to the drawings wherein:

FIG. 1 is an elevational view, partly in section, showing one embodimentof the apparatus of the invention;

FIG. 2 is a sectional view taken along the lines 2-2 of FIG. I, viewedin the direction of the arrows;

FIG. 3 is a sectional view taken along the lines 33 of FIG. 1;

FIG. 4 is an elevational view, partly in section, of a furtherembodiment of the invention.

FIG. 5 is a sectional view along the lines 5-5 of FIG. 4 viewed in thedirection of the arrows.

FIG. 6 is a sectional view along the lines 6-6 of FIG. 4.

FIG. 7 is an elevational view, partly in section, of a furtherembodiment of the invention;

FIG. 8 is a sectional view along the lines 88 of FIG. 7.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS Referring to the drawings, FIGS.1, 2, 3, there is shown an apparatus for processing plastic materialcomprising an increasing housing 22 which has an interior surface 24symmetric to the center line 16 thereof. The interior surface 24 has aninterior circumference increasing from a first circumference, thehousing entrance 25, to the large housing circumference 27. Theincreasing housing 22 is connected near the large housing circumference27 to a decreasing housing 30 which has an interior surface 32 symmetricto the middle line 19 with an interior circumference decreasing from thelarge housing circumference 27 to the circumference 39 of a dischargeopening 38 near the middle line of the decreasing interior surface 32.

A revolving member 10 is surrounded by the housings interior surfaces 24and 32 in spaced relationship to define a processing space 26therebetween. The member 10 has a surface 14 increasing from a firstcircumference, the member entrance circumference 15, to the large membercircumference 17, the increasing surface 14 being symmetric to themember axis 12. The revolving member 10 has a second, decreasing surface18 connecting to the large member circumference I7 and'surrounded by thedecreasing interior surface 32 in spaced relationship to define aprocessing space 34 therebetween. The decreasing surface 18 has acircumference decreasing from said large member circumference 17 towardthe member axis 12. The decreasing surface 18 is also symmetric to themember axis 12.

THe member 10 is revolvably mounted about the axis of revolution 12 fromwhich the center line 16 of the increasing surface 24 has a radialdistance, and from which the middle line 19 of the decreasing surface 32has a radial distance in diametral direction. The means for revolvingthe member are not shown.

The surface 24 of the increasing housing 22 has a gradual transition tothe surface 32 of the decreasing housing 30, and the increasing surface14 of the member 10 has a gradual transition to the decreasing surface18 of the member 10.

TO vary and control the spaced relationship between the revolving member10 and the housing surfaces 24 and 32, the revolving member 10, theincreasing housing 22 and the decreasing housing 30 are axially movablerelatively to each other, the means for exerting such axial movementbeing conventional and not shown.

Means for introducing plastic material in the processing space 26 nearthe entrance circumference comprise a barrel 42 attached to theincreasing housing 22 near the entrance circumference 25. The barrel 42has an interior surface 44 symmetric to the member axis 12. A feed screw46 having helical flights 48 extends through the barrel 42 and isconnected to the revolving member 10 near the member entrancecircumference 15.

The central portion 11 of the member decreasing surface 18 is mountedseparately rotatable about an axis of rotation coincident with themembers axis of revolution 12 and having a radial distance from themiddle line 19 of the members peripheral decreasing surface 18. Thecentral portion 11 is thus rotated independently at a rate differentfrom the increasing surface 14 and the peripheral decreasing surface 18by conventional means not shown.

An extrusion screw 54 coaxial to the member 10 is attached to thecentral portion 11 and extends through the discharge opening 38 in anextrusion barrel 72 which is attached to the decreasing housing and hasan interior surface 80 communicating with the discharge opening 38 andan extrusion opening 84.

The extrusion barrels interior surface 80 decreases radially in axialdirection in a tapering surface 82. The extrusion screw 54 has a taper86 in spaced relationship and tapering correspondingly to the taperingsurface 82. Since the processing-space 34 is varied and controlled bymoving axially the member 10 with the central portion 11 and theextrusion screw 54 relatively to the decreasing housing 30, the spacedrelationship between'the tapering surface 82 and the taper 86 is variedand controlled simultaneously.

In the interior surface 24 of the increasing housing 22, near the largehousing circumference 27, an opening 74 is provided for devolatilizinggases and vapors, and for introducing additives to the plastic materialto be processed.

.ln F105. 4, 5,6, the apparatus for processing plastic materialcomprises an increasing housing 122 which has an interior surface 124symmetric to the center line 116 thereof. The interior surface 124 hasan interior circumference increasing from a housing entrancecircumference 125 to a large housing circumference 127. THe increasinghousing 122 is connected to a decreasing housing 130 which has aninterior surface 132 symmetric to the middle line 119 with an interiorcircumference decreasing from the large housing circumference 127 to thecircumference 139 of a discharge opening 138.

A revolving member is surrounded by the interior surface 124 in spacedrelationship to define a processing space 126 therebetween. The member110 has a surface 114 increasing from a member entrance circumference115 to a large member circumference 117, the increasing surface 114being symmetric to the member axis 112. The member 110 has a decreasingsurface 118 connecting to the large member circumference 117 andsurrounded by the interior surface 132 in spaced relationship to definea processing space 134 therebetween. The decreasing surface 118 has acircumference decreasing from the large member circumference 117 towardthe member axis 112 and is symmetric to the member axis 112 thereof.

The member 110 is revolvably mounted about the axis 112 from which thecenter line 116 of the increasing surface 124 has a radial distance, andfrom which the middle line 119 of the decreasing surface 132 has aradial distance in diametral direction. The decreasing surface 118 endsin a tip 120 which revolves.

To vary and control the spaced relationship between the revolving member110 and the housing surfaces 124 and 132, the revolving member 110, theincreasing housing 122 and the decreasing housing 130 are axiallymovable relatively to each other, the means for exerting such axialmovement being conventional and not shown.

Means for introducing plastic material in the processing space 126 nearthe entrance circumference comprise a barrel 142 attached to theincreasing housing 122. The barrel 142 has an interior surface 144symmetric to the member axis 112. A feed screw 146 having helicalflights 148 extends through the barrel 142 and is connected to therevolving member 110 near the member entrance circumference 115. I

FIGS. 7 and 8 show an apparatus comprising an increasing housing 222which has an interior surface 224 symmetric to the center line 216thereof. The interior surface 224 has a circumference increasing from ahousing entrance circumference 225 to the large housing circumference227. The increasing housing 222 is connected near the large housingcircumference 227 to a decreasing housing 230 which has an interiorsurface 232 symmetric to the middle line 219 with an interiorcircumference decreasing from the large housing circumference 227 to adischarge opening 238 in the center of the decreasing interior surface232.

A revolving member 210 is surrounded by the interior surface 224 inspaced relationship to define a processing space 226 therebetween. Themember 210 has a surface 214 increasing from a member entrancecircumference 215, to a large member circumference 217, the increasingsurface 214 being symmetric to the member axis 212. The revolving member210 has a second decreasing surface 218 connecting to the large membercircumference 217 and surrounded by the interior surface 232 in spacedrelationship to define a processing space 234 therebetween. Thedecreasing surface 218 has a circumference decreasing from the largemember circumference 217 toward the member axis 212 and is symmetric tothat axis 212.

The member 210 is revolvably mounted about the axis 212 from which thecenter line 216 of the increasing surface 224 has a radial distance, andfrom which the middle line 219 of the decreasing surface 232 has aradial distance in diametral direction. The means for revolving themember 210 are not shown.

The increasing surfaces 214, 224 of the member 210 and of the increasinghousing 222 diverge by a small acute angle, and the decreasing surfaces218, 232 of the member 211) and of the decreasing housing 230 alsodiverge by a small acute angle, so that they exert a force on theplastic material in the direction of their divergence.

The increasing surface 214 is provided with depressions 252 extendingbelow the surface 214 so that the plastic material is processed betweenthe surface 214 and the surface 224 in varying material depths. Thedepressions may have any form and may be shaped, for example, spirallyso as to form helical depressions.

To vary and control the spaced relationship between the increasingmember surface 214 and the increasing housing-surface 224, and betweenthe decreasing member surface 218 and the decreasing housing surface232, the revolving member 210, the increasing housing 222 and thedecreasing housing 230 are axially movable relatively to each other, themeans for providing such axial movement being conventional and notshown.

- Means for introducing plastic material in the processing space 226comprise a barrel 242 attaached to the increasing housing 222 near thehousing entrance circumference 225. A feed screw 246 having helicalflights 248 extends through the barrel 242 and is connected to themember 210 near the entrance circumference 215.

The revolving member 210 has a cylindrical bore 256 coaxial to themember axis 212 from which the middle line 219 of the decreasing surface232 has a radial distance. An injection screw 254 is mounted rotatablyin and axially movable through the bore 256, the discharge opening 238,and the injection cylinder 272, by means which are conventional and notshown.

In the various embodiments the difference between the maximum distanceand the minimum distance from the revolving member to the housinginterior surfaces has been distinctly illustrated. It is understood thatthis difference between the maximum distance and the minimum distancemay have any minute size which would be too small to show in thedrawings. It is obvious to anyone skilled in the art that this can beeasily achieved in practice by using a very minute radial distance ofthe housing center line and middle line to the member axis.

In the various embodiments the revolving member and the housing interiorsurfaces are shown for the pun pose of illustration as having roundcross sections. it is understood that these cross sections may haveother shapes, and may be, for example, oblong, oval, octagonal,hexagonal. or may have any other regular or irregular form.

In the various embodiments there is a transition from the barrel surface44 (144,244) which is symmetric to the axis 12 (112,212), to the housingsurface 24 (124,224) which is symmetric to its center line 16 (116,216).it is obvious that over the length of this transition the interiorhousing surface 24 (124,224) is not symmetric to the center line 16(116,216). For the same reason the surface 32 (132), in its transitionto the discharge opening 38 (138), changes its symmetry to the middleline 9 (119) to a symmetry to the axis 12 (112).

Generally speaking, an apparatus for processing plastic material isusually provided with means for heating and cooling, for measuring andrecording tempera tures, pressures, flow rates and other variables. Suchmeans are not shown in the various embodiments, since their illustrationand description would obstruct the drawings and their description. It isobvious to anyone skilled in the art that the apparatus of the inventionis provided with known means for heating and cooling, measuring andrecording of temperatures, pressures, flow rates and other variables.Such means may include, for example, flow passages for heating andcooling fluids in housings, barrels, revolving members and screws, orrevolving elements connected thereto.

In the various embodiments, several surfaces are shown to be providedfor sealing against plastic material, or gases, or hydraulic fluids. Theseals, however, are not shown because of their size and for betterclarity. Also not shown are bolts, screws, and nuts to connect partsshown as being connected, for example shown as being provided withflanges for such connections.

Although the present invention has been described in conjunction withpreferred embodiments, it is to be understood that modifications andvariations may be resorted to without departing from the spirit andscope of the invention as those skilled in the art will readilyunderstand. Such modifications and variations are considered to bewithin the purview and scope of the invention and appended claims.

I claim:

1. Apparatus for processing plastic material comprismg an increasinghousing having an interior surface symmetric to the center line thereof,said interior surface having an interior circumference increasing from afirst circumference, the housing entrance circumference, to the largehousing circumference;

a revolving member surrounded by said housing interior surface in spacedrelationship to define a processing space therebetween, said memberhaving a surface increasing from a first circumference, the memberentrance circumference, to the large member circumference, the member'sincreasing surface being symmetric to the members axis;

said member being mounted revolvably about said axis;

the center line of the increasing housings interior surface having aradial distance from said axis of revolution;

means for revolving said member;

means for introducing plastic material in said processing space nearsaid entrance circumference;

so that during each revolution every point of the revolving memberinterior surface undergoes a change in distance to the housing interiorsurface varying between a maximum and a minimum distance,

thus subjecting the plastic material to a circular and spiral kneadingand milling treatment.

2. Apparatus for processing plastic material as claimed in claim 1wherein said increasing housing is connected near the large housingcircumference to a decreasing housing having an interior surfacesymmetric to the middle line thereof with an interior circumferencedecreasing from said large housing circumference to the circumference ofa discharge opening near the center of said decreasing interior surface;said revolving member having a second, decreasing surface connecting tosaid large member circumference and surrounded by said decreasinginterior surface in spaced relationship to define a processing spacetherebetween, the members decreasing surface having a circumferencedecreasing from said large member circumference toward the members axis,the member's decreasing surface being symmetric to the members axis;said middle line of the decreasing housings interior surface having aradial distance from said axis of revolution in a direction diametral tothe radial distance from said axis of revolution to the center line ofthe increasing housings interior surface; so that the area of smallestdistance between the increasing surfaces of said revolving member andsaid increasing housing is always in diametral position to the area ofsmallest distance between the decreasing surfaces of said revolvingmember and said decreasing housing, thus compensating the effect ofmaximum pressure exerted near the area of smallest distance between thedecreasing surfaces of said revolving member and said decreasing housingby the effect of maximum pressure exerted near the diametral area ofsmallest distance between the increasing surfaces of said revolvingmember and said increasing housmg. 3. Apparatus for processing plasticmaterial as claimed in claim 2 wherein said axis of revolution coincideswith said members center line, and said revolving members largecircumference is larger than said housing entrance circumference, andlarger than the circumference of said discharge opening. 4. Apparatusfor processing plastic material as claimed in claim 2 wherein theincreasing surfaces of said revolving member and of said increasinghousing form with the center lines thereof smaller angles than thedecreasing surfaces of said revolving member and said decreasinghousing, so that theplastic material is subjected to a processingtreatment including a roll mill effect between said increasing surfaces,and is subjected to a processing treatment including the normal forceeffect between said decreasing surfaces. 5. Apparatus for processingplastic material as claimed in claim 2 wherein the increasing surfacesof said revolving member and of said decreasing housing are parallel toeach other, and the decreasing surfaces of said revolving member and ofsaid increasing housing are parallel to each other. 6. Apparatus forprocessing plastic material a claimed in claim 2 wherein the increasingsurfaces of said revolving member and of said increasing housing divergefrom each other by an acute angle. so that the diverging increasingsurfaces exert a force on the plastic material in said processing spacein the direction of divergence of said surfaces.

LII

7. Apparatus for processing plastic material as claimed in claim 2wherein the decreasing surfaces of said revolving member and of saiddecreasing housing diverge from each other by an acute angle, so thatthe diverging decreasing surfaces exert a force on the plastic materialin said processing space in the direction of divergence of saidsurfaces. 8. Apparatus for processing plastic material as claimed inclaim 2 wherein said increasing and decreasing surfaces increase anddecrease linearly so that they form substantially conical surfaces. 9.Apparatus for processing plastic material as claimed in claim 2 whereinsaid surface of said increasing housing has a gradual transition to saidsurface of said decreasing housing, and said increasing surface of saidmember has a gradual transition to said decreasing surface of saidmember. 10. Apparatus for processing plastic material as claimed inclaim 2 wherein,

said surfaces are provided with depressions extending below saidsurfaces, so that the plastic material is processed between saidsurfaces in varying material depths. 11. Apparatus for processingplastic material as claimed in claim 2, wherein means are provided foraxially moving the revolving member, the increasing and the decreasinghousing relatively to each other, so that the spaced relation shipbetween the revolving member and the housing interior surfaces can bevaried and controlled.

12. Apparatus for processing plastic material as claimed in claim 2wherein said means for introducing plastic material comprise a barrelattached to said increasing housing near said housing entrancecircumference, said barrel having an interior surface symmetric to themember axis;

a feed screw extending through said barrel, having helical flights, andbeing connected to said revolving member near said member entrancecircumference,

so that plastic material is conveyed by said feed screw through saidbarrel into the processing space between said revolving member and saidincreasing housing.

13. Apparatus for processing plastic material as claimed in claim 2wherein the central portion of said members decreasing surface ismounted separately rotatable about an axis of rotation coincident withsaid revolving members axis of revolution;

means for rotating said central portion independently, so that saidcentral portion can be rotated at a rate different from the revolvingmembers increasing and peripheral decreasing surfaces.

14. Apparatus for processing plastic material as claimed in claim 2wherein an extrusion screw extends from said members decreasing surfacenear the axis thereof through said discharge opening, said extrusionscrew having an axis coinciding with said members axis, and

an extrusion barrel is attached at the one end thereof to the decreasinghousing, and has an interior surface communicating with said dischargeopening,

so that plastic material processed between said decreasing housing andsaid members decreasing surface is extruded by said extrusion screwthrough said discharge opening and said extrusion barrel.

15. Apparatus for processing plastic material as claimed in claim 14wherein said extrusion barrel has a center line coincident with the axisof said extrusion screw;

the extrusion barrel having an interior surface decreasing radially inaxial direction in a tapering surface;

said extrusion screw having a taper in spaced relationship and taperingcorrespondingly to said tapering surface;

means for axially moving said revolving member with said extrusionscrew, and said decreasing housing with said extrusion barrel relativelyto each other,

so that the spaced relationship between said revolving member and saiddecreasing housing and between said taper and said tapering surface canbe varied and controlled simultaneously. 16. Apparatus for processingplastic material as claimed in claim 13 wherein said central portion ofsaid member has attached an extrusion screw coaxial to said centralportion and extending through said discharge opening and in an extrusionbarrel attached to said decreasing housmg. 17. Apparatus for processingplastic material as claimed in claim 2 wherein said revolving member hasa cylindrical bore coaxial with said members axis, having a radialdistance from the center line of said increasing housing and from themiddle line of said decreasing housing; an injection screw mountedrotatably in and axially movable through said bore and said dischargeopening; means for rotating and axially moving said injection screw. 18.Apparatus for processing plastic material as claimed in claim 2 whereinsaid revolving member has a cylindrical bore coaxial with said membersaxis, having a radial distance from the middle line of said decreasinghousing; an injection piston being mounted in and axially movablethrough said bore and through said discharge opening; means beingprovided for axially moving said injection piston. 19. Apparatus forprocessing plastic material as claimed in claim 2 wherein an opening isprovided in the housing interior surface near said large housingcircumference for devolatilizing gases and vapors, and for introducingadditives to the plastic material to be processed. 20. Apparatus forprocessing plastic material as claimed in claim 3 wherein the increasingsurfaces of said revolving member and of said increasing housing formwith the center lines thereof smaller angles than the decreasingsurfaces of said revolving member and said decreasing housing;

said means for introducing plastic material comprising a barrel attachedto said increasing housing near said housing entrance circumference,said barrel having an interior surface symmetric to the revolvingmembers axis, and

a feed screw extending through said barrel, having helical flights andbeing connected to said revolving member near said member entrancecircumference;

an extrusion barrel attached at the one end thereof to and coaxial withsaid revolving member, having an interior surface communicating withsaid discharge opening on said one end and an extrusion opening on theother end, and decreasing radially in axial direction in a taperingsurface;

an extrusion screw extending from said members decreasing surfacethrough said discharge opening, said extrusion screws axis beingcoincident with the members axis, the extrusion screw having a taper inspaced relationship and tapering correspondingly to said taperingsurface;

means being provided for axially moving said revolving member with saidfeed screw and said extrusion screw, said increasing housing, and saiddecreasing housing with said extrusion barrel relatively to each other,

so that the spaced relationship between said increasing housing surfaceand said member increasing surface, between said decreasing housingsurface and said member decreasing surface, and between said taperingsurface and said taper can be varied and controlled simultaneously.

21. Apparatus for processing plastic material as claimed in claim 4wherein the increasing surfaces of said revolving member and saidincreasing housing diverge from each other by an acute angle, and

the decreasing surfaces of said revolving member and said decreasinghousing diverge from each other by an acute angle;

said surfaces being provided with depressions extending below saidsurfaces;

said means for introducing plastic material comprising a barrel attachedto said increasing housing near said housing entrance circumference,said barrel having an interior surface symmetric to the member axis, and

a feed screw extending through said barrel, having helical flights, andbeing connected to said revolving member near said member entrancecircumference;

means being provided for axially moving said revolving member with saidfeed screw, said increasing housing with said barrel, and the decreasinghousing relatively to each other, so that the spaced relationshipbetween the revolving member and the housing interior surfaces can bevaried and controlled;

said revolving member having a cylindrical bore coaxial with saidmembers axis, having a radial distance from the middle line of saiddecreasing housmg;

an injection screw mounted rotatably and axially movable through saidbore and said discharge opening;

means for rotating and axially moving said injection screw. 22.Apparatus for processing plastic material comprising a decreasinghousing having an interior surface symmetric to the center line of saidhousing, and decreasing from a first circumference, the large housingcircumference, to the circumference of a discharge opening near thecenter of said decreasing interior surface;

a revolving member surrounded by said housing interior surface in spacedrelationship to define a processing space therebetween, said memberhaving a surface decreasing from a first circumference, the large membercircumference, toward the center ing and milling treatment.

1. Apparatus for processing plastic material comprising an increasinghousing having an interior surface symmetric to the center line thereof,said interior surface having an interior circumference increasing from afirst circumference, the housing entrance circumference, to the largehousing circumference; a revolving member surrounded by said housinginterior surface in spaced relationship to define a processing spacetherebetween, said member having a surface increasing from a firstcircumference, the member entrance circumference, to the large membercircumference, the member''s increasing surface being symmetric to themember''s axis; said member being mounted revolvably about said axis;the center line of the increasing housing''s interior surface having aradial distance from said axis of revolution; means for revolving saidmember; means for introducing plastic material in said processing spacenear said entrance circumference; so that during each revolution everypoint of the revolving member interior surface undergoes a change indistance to the housing interior surface varying between a maximum and aminimum distance, thus subjecting the plastic material to a circular andspiral kneading and milling treatment.
 2. Apparatus for processingplastic material as claimed in claim 1 wherein said increasing housingis connected near the large housing circumference to a decreasinghousing having an interior surface symmetric to the middle line thereofwith an interior circumference decreasing from said large housingcircumference to the circumference of a discharge opening near thecenter of said decreasing interior surface; said revolving member havinga second, decreasing surface connecting to said large membercircumference and surrounded by said decreasing interior surface inspaced relationship to define a processing space therebetween, themember''s decreasing surface having a circumference decreasing from saidlarge member circumference toward the member''s axis, the member''sdecreasing surface being symmetric to the member''s axis; said middleline of the decreasing housing''s interior surface having a radialdistance from said axis of revolution in a direction diametral to theradial distance from said axis of revolution to the center line of theincreasing housing''s interior surface; so that the area of smallestdistance between the increasing surfaces of said revolving member andsaid increasing housing is always in diametral position to the area ofsmallest distance between the decreasing surfaces of said revolvingmember and said decreasing housing, thus compensating the effect ofmaximum pressure exerted near the area of smallest distance between thedecreasing surfaces of said revolving member and said decreasing housingby the effect of maximum pressure exerted near the diametral area ofsmallest distance between the increasing surfaces of said revolvingmember and said increasing housing.
 3. Apparatus for processing plasticmaterial as claimed in claim 2 wherein said axis of revolution coincideswith said member''s center line, and said revolving member''s largecircumference is larger than said housing entrance circumference, andlarger than the circumference of said discharge opening.
 4. Apparatusfor processing plastic material as claimed in claim 2 wherein theincreasing surfaces of said revolving member and of said increasinghousing form with the center lines thereof smaller angles than thedecreasing surfaces of said revolving member and said decreasinghousing, so that the plastic material is subjected to a processingtreatment including a roll mill effect between said increasing surfaces,and is subjected to a processing treatment including the normal forceeffect between said decreasing surfaces.
 5. Apparatus for processingplastic material as claimed in claim 2 wherein the increasing surfacesof said revolving member and of said decreasing housing are parallel toeach other, and the decreasing surfaces of said revolving member and ofsaid increasing housing are parallel to each other.
 6. Apparatus forprocessing plastic material as claimed in claim 2 wherein the increasingsurfaces of said revolving member and of said increasing housing divergefrom each other by an acute angle, so that the diverging increasingsurfaces exert a force on the plastic material in said processing spacein the direction of divergence of said surfaces.
 7. Apparatus forprocessing plastic material as claimed in claim 2 wherein the decreasingsurfaces of said revolving member and of said decreasing housing divergefrom each other by an acute angle, so that the diverging decreasingsurfaces exert a force on the plastic material in said processing spacein the direction of divergence of said surfaces.
 8. Apparatus forprocessing plastic material as claimed in claim 2 wherein saidincreasing and decreasing surfaces increase and decrease linearly sothat they form substantially conical surfaces.
 9. Apparatus forprocessing plastic material as claimed in claim 2 wherein said surfaceof said increasing housing has a gradual transition to said surface ofsaid decreasing housing, and said increasing surface of said member hasa gradual transition to said decreasing surFace of said member. 10.Apparatus for processing plastic material as claimed in claim 2 whereinsaid surfaces are provided with depressions extending below saidsurfaces, so that the plastic material is processed between saidsurfaces in varying material depths.
 11. Apparatus for processingplastic material as claimed in claim 2, wherein means are provided foraxially moving the revolving member, the increasing and the decreasinghousing relatively to each other, so that the spaced relationshipbetween the revolving member and the housing interior surfaces can bevaried and controlled.
 12. Apparatus for processing plastic material asclaimed in claim 2 wherein said means for introducing plastic materialcomprise a barrel attached to said increasing housing near said housingentrance circumference, said barrel having an interior surface symmetricto the member axis; a feed screw extending through said barrel, havinghelical flights, and being connected to said revolving member near saidmember entrance circumference, so that plastic material is conveyed bysaid feed screw through said barrel into the processing space betweensaid revolving member and said increasing housing.
 13. Apparatus forprocessing plastic material as claimed in claim 2 wherein the centralportion of said member''s decreasing surface is mounted separatelyrotatable about an axis of rotation coincident with said revolvingmember''s axis of revolution; means for rotating said central portionindependently, so that said central portion can be rotated at a ratedifferent from the revolving member''s increasing and peripheraldecreasing surfaces.
 14. Apparatus for processing plastic material asclaimed in claim 2 wherein an extrusion screw extends from saidmember''s decreasing surface near the axis thereof through saiddischarge opening, said extrusion screw having an axis coinciding withsaid member''s axis, and an extrusion barrel is attached at the one endthereof to the decreasing housing, and has an interior surfacecommunicating with said discharge opening, so that plastic materialprocessed between said decreasing housing and said member''s decreasingsurface is extruded by said extrusion screw through said dischargeopening and said extrusion barrel.
 15. Apparatus for processing plasticmaterial as claimed in claim 14 wherein said extrusion barrel has acenter line coincident with the axis of said extrusion screw; theextrusion barrel having an interior surface decreasing radially in axialdirection in a tapering surface; said extrusion screw having a taper inspaced relationship and tapering correspondingly to said taperingsurface; means for axially moving said revolving member with saidextrusion screw, and said decreasing housing with said extrusion barrelrelatively to each other, so that the spaced relationship between saidrevolving member and said decreasing housing and between said taper andsaid tapering surface can be varied and controlled simultaneously. 16.Apparatus for processing plastic material as claimed in claim 13 whereinsaid central portion of said member has attached an extrusion screwcoaxial to said central portion and extending through said dischargeopening and in an extrusion barrel attached to said decreasing housing.17. Apparatus for processing plastic material as claimed in claim 2wherein said revolving member has a cylindrical bore coaxial with saidmember''s axis, having a radial distance from the center line of saidincreasing housing and from the middle line of said decreasing housing;an injection screw mounted rotatably in and axially movable through saidbore and said discharge opening; means for rotating and axially movingsaid injection screw.
 18. Apparatus for processing plastic material asclaimed in claim 2 wherein said revolving member has a cylindrical borecoaxial with said member''s axis, having a radial distance From themiddle line of said decreasing housing; an injection piston beingmounted in and axially movable through said bore and through saiddischarge opening; means being provided for axially moving saidinjection piston.
 19. Apparatus for processing plastic material asclaimed in claim 2 wherein an opening is provided in the housinginterior surface near said large housing circumference fordevolatilizing gases and vapors, and for introducing additives to theplastic material to be processed.
 20. Apparatus for processing plasticmaterial as claimed in claim 3 wherein the increasing surfaces of saidrevolving member and of said increasing housing form with the centerlines thereof smaller angles than the decreasing surfaces of saidrevolving member and said decreasing housing; said means for introducingplastic material comprising a barrel attached to said increasing housingnear said housing entrance circumference, said barrel having an interiorsurface symmetric to the revolving member''s axis, and a feed screwextending through said barrel, having helical flights and beingconnected to said revolving member near said member entrancecircumference; an extrusion barrel attached at the one end thereof toand coaxial with said revolving member, having an interior surfacecommunicating with said discharge opening on said one end and anextrusion opening on the other end, and decreasing radially in axialdirection in a tapering surface; an extrusion screw extending from saidmember''s decreasing surface through said discharge opening, saidextrusion screw''s axis being coincident with the member''s axis, theextrusion screw having a taper in spaced relationship and taperingcorrespondingly to said tapering surface; means being provided foraxially moving said revolving member with said feed screw and saidextrusion screw, said increasing housing, and said decreasing housingwith said extrusion barrel relatively to each other, so that the spacedrelationship between said increasing housing surface and said memberincreasing surface, between said decreasing housing surface and saidmember decreasing surface, and between said tapering surface and saidtaper can be varied and controlled simultaneously.
 21. Apparatus forprocessing plastic material as claimed in claim 4 wherein the increasingsurfaces of said revolving member and said increasing housing divergefrom each other by an acute angle, and the decreasing surfaces of saidrevolving member and said decreasing housing diverge from each other byan acute angle; said surfaces being provided with depressions extendingbelow said surfaces; said means for introducing plastic materialcomprising a barrel attached to said increasing housing near saidhousing entrance circumference, said barrel having an interior surfacesymmetric to the member axis, and a feed screw extending through saidbarrel, having helical flights, and being connected to said revolvingmember near said member entrance circumference; means being provided foraxially moving said revolving member with said feed screw, saidincreasing housing with said barrel, and the decreasing housingrelatively to each other, so that the spaced relationship between therevolving member and the housing interior surfaces can be varied andcontrolled; said revolving member having a cylindrical bore coaxial withsaid member''s axis, having a radial distance from the middle line ofsaid decreasing housing; an injection screw mounted rotatably andaxially movable through said bore and said discharge opening; means forrotating and axially moving said injection screw.
 22. Apparatus forprocessing plastic material comprising a decreasing housing having aninterior surface symmetric to the center line of said housing, anddecreasing from a first circumference, the large housing circumference,to the circumference of a discharge opening near the center of saiddecreasing intErior surface; a revolving member surrounded by saidhousing interior surface in spaced relationship to define a processingspace therebetween, said member having a surface decreasing from a firstcircumference, the large member circumference, toward the center linethereof, the member''s surface being symmetric to the axis thereof; saidmember being mounted revolvably about said axis having a radial distanceto the member''s center line; means for revolving said member; means forintroducing plastic material in said processing space near said largecircumference, so that during each revolution every point of therevolving member undergoes a change in distance to the decreasinghousing surface varying between a maximum and a minimum distance, thussubjecting the plastic material to a circular and spiral kneading andmilling treatment.